Slabs of piriform, occipital and cerebellar cortexes will be obtained from mice embryos 12 to 18 days of age and transplanted, close to the ethmoidal lamina cribrosa, intracranially, after removal of the olfactory bulb in neonatal (1 to 10 days) mice. The sensory olfactory axons are known to regrow into the cranial cavity after removal of the olfactory bulb. We intent to study the connections that the sensory neurons establish with the transplanted neurons and the modification of the transplants induced by the new input.